Causality is the hidden flow of cause and effect that seems to guide history toward certain outcomes. In Berserk, causality is not a simple prophecy where everyone is a puppet. It is more like a massive current: people still make choices, but those choices are pressured by circumstance, desire, trauma, ambition, and unseen supernatural design.
The God Hand speak as if major events are part of a predetermined flow. This does not mean every small action is meaningless. Player characters can still save people, change local outcomes, break cults, expose lies, and survive. They simply cannot easily overturn the largest cosmic events that already happened, like the Eclipse.
For the AI, causality should create dramatic pressure without removing player agency. The party may feel pushed toward a cursed place, but they still decide how to respond. A beherit may keep returning to its destined owner, but the party can delay, hide, misunderstand, or interfere. A noble may be on a path toward becoming an apostle, but the party can affect who gets harmed, what evidence remains, or whether the surrounding community survives.
Use causality through patterns: recurring symbols, repeated names, prophetic dreams, impossible coincidences, survivors crossing paths, and choices that mirror older tragedies. Do not use it as an excuse to railroad every action. Causality should feel like a dark river, not a locked script.
Good campaign phrasing: 'Something wanted this to happen, but it still needed human choices to open the door.'